Midlatitude cirrus cloud radiative forcing over China
Midlatitude cirrus cloud radiative forcing over China
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DOI：
10.1029/2010jd014161
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发表时间：
2010-10
影响因子：
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通讯作者：
Min Min-Min;Pucai C. Wang;J. Campbell;Xuemei Zong;Y. Li
中科院分区：
文献类型：
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作者：
Min Min-Min;Pucai C. Wang;J. Campbell;Xuemei Zong;Y. Li
利用正交偏振地球轨道云气溶胶激光雷达（CALIOP）和中分辨率成像光谱仪（MODIS）测量初始化的辐射传输模式估算了中国对流层顶中纬度卷云辐射强迫（CRF）值。推导出的日平均CRF作为太阳天顶角的函数来求解，θ虽然在太阳日上变化，但用于评估θ对CRF计算的灵敏度和影响。虽然利用直接观测资料估计的总平均净CRF为36.5±48.4 W m−2，与从日平均模拟得到的36.8±50.4 W m−2大致相同，但月差异说明了θ对CRF影响的季节性函数。这一发现可归因于在较高地形上观测到的卷云的增温效应更为突出。此外，夏季高原上空温暖湿润的热廓线导致高原上空长波（LW）和净CRF减少。卷云可见光深度的季节空间变异性也有助于相应的短波（SW）、LW和NET CRF解的空间变异性。
Midlatitude cirrus cloud radiative forcing (CRF) values at the tropopause over China are estimated using a radiative transfer model initialized by Earth‐orbiting Cloud‐Aerosol Lidar with Orthogonal Polarization (CALIOP) and Moderate Resolution Imaging Spectroradiometer (MODIS) measurements. A derived diurnal mean CRF, solved as a function of solar zenith angle, θ, though varied over the solar day, is used to evaluate the sensitivity and influence of θ on CRF calculations. Although a total mean net (NET) CRF of 36.5 ± 48.4 W m−2, estimated using direct observation data, is approximately equal to the value of 36.8 ± 50.4 W m−2 from the diurnal mean simulations, monthly differences illustrate a seasonality function dictating the influence of θ on CRF. A significant positive NET effect exceeding ∼ 80 W m−2 over the Qinghai‐Tibet Plateau is found, which is in contrast to a NET CRF found to be closer to 20 W m−2 for most parts of China. This finding is attributable to a more prominent warming effect of cirrus clouds observed over higher terrain. Furthermore, a warmer and more humid thermal profile over the high terrain in summer induces decreases in longwave (LW) and NET CRF over the plateau. The seasonal spatial variability of cirrus cloud visible optical depths also contributes to the corresponding spatial variability of shortwave (SW), LW, and NET CRF solved.